A Case Report & Literature Review D. G. Kang et al Multifocal Intraosseous Ganglioneuroma Daniel G. Kang, MD, Melvin D. Helgeson, MD, Jennifer D. Britt, DMD, Robert W. Tracey, MD, and Joshua D. Bernstock, MS, MPH showed a “ground-glass” appearance consistent with fibrous Abstract dysplasia rather than hemangioma (Figure 1B). A skeletal sur- We report a case of asymptomatic intraosseous vey showed mixed lytic-sclerotic lesions (central lucency with ganglioneuroma of the ilium, which was initially peripheral margin of sclerosis) in the right ilium just above misdiagnosed as polyostotic fibrous dysplasia. Our the acetabulum (4.5 × 5.2 cm) and a smaller lesion in the left patient presented with multiple asymptomatic skel- ilium (1.1 × 1.8 cm; Figure 2). Additionally, lytic, well-defined etal lesions. Despite extensive work-up of our patient lesions were identified in the distal left humerus (4.1 × 2.0 cm), to rule out metastatic disease, we were unable to find a primary source; biopsy showed intraosse- ous ganglioneuroma of the ilium. To the best of our knowledge, we report an exceedingly rare pathologic Figure 1. (A) Sagittal T2-weighted magnetic resonance imaging of brain and (B) computed tomography of head show expansile entity; only 3 cases have been described of intraos- lesion in clivus. seous ganglioneuroma from spontaneous cytomatu- ration of metastatic neuroblastoma. A B Knowledge of the natural history of ganglio- neuroma is limited, but patients with primary and multifocal disease appear to have benign histologic tumor appearance and excellent prognoses. Similar to previous studies, the rarity of this tumorAJO and its nonspecific radiographic and clinical presentation resulted in the correct diagnosis only after histo- pathologic analysis. Because intraosseous ganglio- neuroma may mimic fibrous dysplasia it should be considered in the differential diagnosis of benign- appearing skeletal lesions, particularly if the patient has a history of neuroblastoma. DO NOTFigure 2. PlainCOPY anteroposterior radiograph of pelvis show lytic lesions with sclerotic margins. anglioneuromas are rare, enigmatic tumors consid- ered to be the benign subset of neuroblastic tumors.1,2 G An extensive review of the literature revealed only 3 case reports of intraosseous ganglioneuroma developing from spontaneous differentiation of metastatic neuroblastoma.3-5 We report a case of asymptomatic intraosseous ganglioneuroma of the ilium, which was initially misdiagnosed as polyostotic fibrous dysplasia. The patient provided written informed con- sent for print and electronic publication of this case report Case Report A 51-year-old man was initially evaluated for persistent head- aches by the neurology service, and magnetic resonance im- aging (MRI) of the brain showed an unusual expansile lesion in the clivus with low T1-signal and high T2-signal intensity (Figure 1A). Computed tomography (CT) imaging of the head Authors’ Disclosure Statement: The views expressed in this manuscript are those of the authors and do not reflect the official policy of the Depart- ment of Army, Department of Defense, or US Government. The authors report no actual or potential conflict of interest in relation to this article. E232 The American Journal of Orthopedics® October 2014 www.amjorthopedics.com A Case Report & Literature Review D. G. Kang et al A A B B Figure 3. (A, B) Axial computed tomography imagesAJO of pelvis. Figure 4. (A, B) Axial T2-weighted magnetic resonance imaging of left proximal femoral diaphysis (5.6 × 1.1 cm), and left proxi- pelvis. mal tibia diaphysis (10.0 × 1.5 cm). These multiple skeletal lesions were asymptomatic, and based on characteristic radio- graphicDO findings, the patient wasNOT diagnosed with polyostotic characterized COPY on the C/A/P CT images, and MRI of the pelvis fibrous dysplasia; treatment consisted of observation. showed multiple mixed lytic and sclerotic lesions in the pelvis The patient was referred to the orthopedic oncology clinic (CT: “ground-glass” appearance; MRI: low signal intensity on 3 years, 5 months after initial presentation for evaluation and T1-weighted images and high signal intensity on T2-weighted skeletal lesion biopsy because of concern for metastatic disease images), expansile-elongated lesions of the right fifth and of unknown origin. The patient reported that a neuroblastoma sixth posterior ribs, and multiple sclerotic densities through- tumor was removed from his mediastinum at 10 years of age, out the lower thoracic and lumbar spine (Figures 3 and 4). with no chemotherapy or radiation therapy. Attempts to re- Technetium-99m scintigraphy showed a subtle focus of mildly trieve his 1960s medical record and a query of the Armed Forc- increased tracer activity in the right supra-acetabular ilium, es Institute of Pathology (AFIP) for an archived tissue sample/ along with multiple other areas of increased activity that could report were unsuccessful. On physical examination, the patient indicate metastatic disease, such as the proximal right femur, appeared cachectic because of a recent involuntary 50-pound mid-left femoral diaphysis, proximal left tibia diaphysis, and weight loss; however, the remainder of his musculoskeletal and bilateral scapulae (Figure 5). neurologic examination was unremarkable. Laboratory stud- Although radiographic findings suggested polyostotic fi- ies also showed normal findings, which included a complete brous dysplasia (irregularly defined, hazy radiolucency with blood cell count with differential analysis, liver function tests, a zone of reactive sclerosis and involvement of the ribs),3,6 the alkaline phosphatase, basic metabolic panel (electrolytes, renal uncertainty of metastatic disease of unknown origin and the function tests), erythrocyte sedimentation rate, thyroid func- patient’s clinical presentation warranted biopsy. Initially, we tion tests, parathyroid hormone level, prostate serum antigen, attempted CT-guided percutaneous needle biopsy of the right and lactate dehydrogenase level. ilium lesion; this was unsuccessful because of inadequate tis- A metastatic disease work-up, which included chest/abdo- sue sampling. Subsequently, we performed an intralesional men/pelvis (C/A/P) CT imaging with contrast, did not show biopsy of the right ilium (periacetabular) lesion, which showed a primary source of disease. The skeletal lesions were further ganglioneuroma, and AFIP review confirmed it. The hema- www.amjorthopedics.com October 2014 The American Journal of Orthopedics® E233 Multifocal Intraosseous Ganglioneuroma D. G. Kang et al toxylin-eosin–stained surgical specimen showed a neoplasm composed of bland “wavy” spindle cells admixed with large epithelioid ganglion cells. Fragments of vital cortical bone were identified within the loose, variably myxoid, fibrous connec- tive tissue stroma (Figures 6A, 6B). The neoplastic cells were strongly immunoreactive for S-100 protein (Figure 7). We did not identify any malignant features, and the histopathologic features supported interpretation as ganglioneuroma. At 5-year follow-up, the patient remains asymptomatic without interval radiographic changes to the skeletal lesions. The patient reports his weight has remained stable since his initial presentation, and the reported involuntary weight loss 5 years ago has been attributed to a diagnosis of polymyalgia rheumatica. Discussion Neuroblastic tumors include neuroblastoma, ganglioneuro- blastoma, and ganglioneuroma, with each derived from pri- mordial neural crest cells that form the sympathetic nervous system.2 However, each is of varying maturity and malignancy potential, ranging from neuroblastoma, which is the most immature, undifferentiated, and malignant tumor, to benign ganglioneuroma, which is composed entirely of gangliocytes and mature Schwannian stroma, without neuroblasts, cel- lular atypia, mitotic activity, or necrosis.2,3 Neuroblastoma is the most common extracranial malignant solid tumor of AJOchildhood, found most frequently in the posterior mediasti- num, retroperitoneum, adrenal gland, and neck, and is often diagnosed during the first 3 years of life.2,4 Bone is the most common site of metastasis, present in up to two-thirds of patients at the time of diagnosis, and is associated with a low rate of survival.2,3,7 In 1927, Cushing and Wolbach8 described the phenomena of clinical regression and histologic maturation of a neuroblas- Figure DO 5. Technetium-99m bone scanNOT with multiple areas of COPY 8 increased tracer activity. toma to ganglioneuroma. Controversy continues regarding the natural history of neuroblastoma, and the prevalence of A B Figure 6. Excisional biopsy from the left ilium shows a neoplasm composed of bland “wavy” spindle cells admixed with large epithelioid ganglion cells. Fragments of vital cortical bone are identified within the loose, variably myxoid, fibrous connective tissue stroma. (A) hematoxylin-eosin (H&E), original magnification ×4; (B) H&E, original magnification ×20. E234 The American Journal of Orthopedics® October 2014 www.amjorthopedics.com Multifocal Intraosseous Ganglioneuroma D. G. Kang et al neuroblasts.1,2 This theory is further supported by the fact that skeletal metastases of neuroblastoma appear to be polyostotic with a predilection for long bones and spine. These were the predominant sites in our patient, as in all 3 previously reported cases of disseminated skeletal ganglioneuroma.3,13 Our patient’s history of a mediastinal neuroblastoma tumor as a child treated with excisional biopsy without chemotherapy or radiation